Detailed analyses of quantities and units of measure in historical documents may also
use the feature structure mechanism described in chapter 19 Feature Structures. The num element is intended for use in simple applications.
예
<p>I reached <num type="cardinal" value="21">twenty-one</num> on my <num type="ordinal" value="21">twenty-first</num> birthday</p> <p>Light travels at <num value="3E10">3×10<hi rend="sup">10</hi> </num> cm per second.</p>